Artificial leg



Sept. 16,1958

Filed June 20, 1955 M. CAPELLA VALENTl ARTIFICIAL LEG 4 Sheets-Sheet 1lNVENTO R MARIO CAPELLA VALEN r:

P 1953 M. CAPELLA VALENTI 2,851,694

ARTIFICIAL LEG 4 Sheets-Sheet 2 Filed June 20, 1955 INVENTOR l MARIOCAPELLA VALENTI p 1958 M. CAPELLA VALENTI 2,851,694

ARTIFICIAL LEG Filed June 20, 1955 4 Sheets-Sheet 3 Se t. 16, 1958' M.CAPELLA VALENTl 2,851,694

ARTIFICIAL LEG Filed June 20, 1955 4 Sheets-Sheet 4 Fig.3

Fig. 10

INVENTOR MARIO CAPELLA VALENT! .leg or part thereof of the wearer. "bersare interconnected through anarticulated shaft and .through aspringmember associated with a braking or the leg or part-thereof of thewearer.

United States Patent cc This'invention relates to tin-artificial legwith a correspondingfoot for below-knee amputees or for deformed:persons with considerable shortening of one lower extremity. In bothcases the person equipped with the apparatus according to the invention.is able to walk in :a substantially normal way both over flat: groundand it over inclined or undulating ground.

This invention is an improvement in or development =1of..theartificial'foot described in the applicants earlier sPatent No.2,446,042,whichrelates:solely to an'arti- .:ficial. 'foot'comprising ahollow foot within which is a -mechanism comprising two members whichare articulated .to one another and one of which .is connected tothesbase of the artificial foot, whilethe othermember is connected to aframework or assembly fixed to the The said two memdamping member.

vThe device according to the present invention com- .prises both footandleg. The artificial foot is alsohollow and contains the articulationmechanism consisting of two parts, one of which is fixed to the base ofthe hollow foot and the other of which is fixed to a framework orassembly associated with the artificial leg and fixed to The two partsof the foot are articulated to one another by means of a shaft disposedat the level of the normal ankle jointand .are interconnected throughthe medium of a 'rod or spring-loaded"connecting member which always:returns .thefoot to :the initial position after an oscillation of the:.foot during walking. The :said'mechanism also 'comprises-awetarding orfriction .member which acts upon the said spring-like member in order tovary the action Ithereof accurately, constantly and operatively independence upon the inclination ofthe groundover which the weareriswalking. With thisarrangement, there- :sult is obtained that a personequipped with this artificial'foot and leg can walk withoutdiificulty.over any type of ground whatever the inclination and nature thereof butdoes;not'undergo any more fatigue than would be felt by a normal personwalking over this type of ground.

For a better understanding of the invention andto show 'how' the samecanbe :carried intoeifect, reference "will now be vmade to theaccompanying drawings,

wherein: p 1

Figure 1 is aside elevation of thecombin'ation forming the artificial"foot' and bywhich is fitted in this case mechanism within thehollow'foot, in the same position as Figure 1;

Figure 4 is a'front elevation of the last-mentioned I mechanism;

2,851,694 Patented Sept. 16, 1958 Figure 5 is a verticalsection thereof:along'theline V--V of Figure'4;

Figure 6 is an outer, partcutaway viewfrom the side "opposite'to thatshown in Figure 3;

:nism contained in therfoot as:shownin Figure' 8, whilst Figure 10 is asection 'alongthe line X-X*:of Figure- 9.

The form of construction illustrated: inFigures .1 'to 71is particularlysuitable for cases where the legdias ibeen amputated below the knee,andcomprises 'aihollow'ffoot formed by two parts 1-'2 whichacontain thearticulation mechanism of the saidfoot, which is in turn combined with ametal framework. or assembly which forms the artificial leg proper andwhich is fixed to the wearers stump. This fixing assembly must obviouslyvary in dependence upon the conditions-.ofzeach case, but inmost casesthe arrangement illustratedin Figuresl and 2 will be used for amputees.

In order to ensurethat sthe-,foot.,1-can execute the movementsnecessary. for walking as if itwere'a normal foot, the two halves '3 and5.of..t l 1e mechanism are interconnectedthrough thetrnedium of'aresilient rodtor resilient connecting member formed by .arhollowcylinder 10 articulated at 11 to the upper half 5.and having in. itsinterior a rod 12 terminating in a piston-like disc '13 actuated by aspring .14. .The bottom .ofthe rod 12 is articulated, through the mediumof the shaft 15,to lugs 30 associated with a member 28 situatedin thelower. half 3. While the wearer is walking over fiat ground, thearticulation shaft 15 remains stationary =and.serves as abearingpointfor the spring-loaded rod 10, with,the resultthat, when the wearer rests.the foot on the ground while walking and when thespring14 iscompressed, the lower member 3 andlfoot ,1 can return to the initialposition from the instant that thiscompres'sion ceases.

In order to facilitate movement of the foot Without tiring the wearerwhen he is walking'up or down an incline, it is arranged according totheinvention that the articulationpoint v15 of the. ro'd,12:can changeits position in dependence upon the inclination of the ground and uponthe direction ofmovement in .order that the foot 1, when lifted clearofthe, ground during movement along an inclination, may not return.ofitself into the position as shown in 'Figurel but may. remain in aposition which is always related to the direction of the ground. Theresult is therefore .obtained that the wearer need not make. an effortateverystep to adapt the 'foot to the inclination of'the ground even inthe case in which, while the wearer is walkingralong a slope, thedirection thereof or of walking changes abruptly.

To this end, there is disposed in the lower'half 3 of the mechanism ashort tubular piece 20 within which is a helicoidal spring 19, one ofthe ends of which is fixed to the cover 21 fixed to the member-3, andthe other end of which is fixed to a cover 22'having projections 23engaging in recesses '24 in the short tubular piece 20.

The latter isfixed to the lower'half 3 of the'mechanism by meansof aclamp" 25fixed to the base of themember 3 by-screws 26 and adapted to'be' tightened by means of the screw 27. The soleobject'of the clamp 25-isto' act as a brake upon the cylinder 20. The pressure of .the

clamp 25 is always 'regulated in "dependence 'upon' the able to turnwhen thewearer displaces "the "centre of gravity of :his body aas=occursin walking up ordow-n 3 inclines, when the piece 20 adapts the foot toinequalities of this type.

Also fixed in the piece 20 is a second clamp 28 which is tightened bymeans of the screw 29 and which has at its upper end lugs 30 to whichthe end of the rod 12 is articulated by means of the shaft 15. The clamp28 determines the point of articulation 15 for the rod 12 and thustransmits to the foot 1 the movement which may be experienced by thebody of the wearer according to the position of his centre of gravity,depending upon the steepness of the inclination of the ground over whichhe is walking. Moreover, by slackening the clamp 28 it is possible toadjust the mechanism, the tensioning of the spring 19 in the piece 20being varied in dependence upon the muscular force of the wearer and asthe complement of the pressure exerted upon the said piece 20 by theclamp 28 through the medium of the action of the screw 29.

One of the lugs 30 has a lateral projection 37 which, when the piece 20turns with the clamp 28, slides upon a curved part 38 of the metal sheetforming the lower part of the mechanism. The curvature of the said metalsheet is such as to limit the movement of the articulation 3015.

When the wearer is walking over fiat ground, the piece 20 and themembers associated therewith take up the position shown in Figure 5, andmovement of the foot only occurs in one direction which is the directionof dorsal extension and which is due to the weight of the wearers bodyat the instant of walking, while the return movement is due solely tothe action of the spring 14.

On the other hand, when the wearer has to pass from flat to inclinedground, the displacement of the centre of gravity of the body massexerts a greater force upon the movable part of the foot, so that thepiece 20 together with the clamp and helicoidal spring 19 causes thearticulation shaft 15 of the spring-loaded rod 12 to vary its positionautomatically, the foot 1 thus being enabled to adapt itself to theinclination of the ground upon which it is resting. Thus, when thewearer lifts the foot clear of the ground, the sole of the foot remainsnot in a horizontal position but in a position which is always dependentupon the steepness of inclination of the ground, with the result that,when the wearer bears upon the foot again, he does not have to make anyeffort to adapt the foot to the inclination of the ground.

The artificial leg proper, that is to say the framework for fixing theartificial foot to the part 16 of the wearers leg is formed by verticalmembers 3132 on each side of the upward extension 8 of the foot. Fixedin the top of the members 3132 is a short metal tubular piece 33 whichis adapted to the leg below the knee. The free ends of the tubular piece33 are articulated by means of shafts 34 corresponding to the rotationalcentre of the knee, to upper upwardly extending parts 35 which support asecond brace 36 which fits the front half of the thigh somewhat abovethe knee, the brace 36 being fixed to this part of the thigh by means ofstraps 17-18.

The short tubular piece is a metal member produced from a moulding takenof the stump or terminal part of the wearers leg 16, the said member 33being such as to surround completely the stump and to be completelyadapted to the contour thereof. On the other hand, the bottom of thetubular piece 33 is opened so that the leg 16 projects downwardly asindicated by the chain lines in Figure 1. In this way a very intimatefit is obtained of the tubular piece 33 upon the leg 16, the lower endthereof being left free so that the artificial foot can be worn withgreater comfort.

The upper brace 36 is also made of metal and is also constructed from amoulding of the part to which the brace 36 is to be applied in order toobtain an exact fit. The central part of the front face of the brace 36has a relatively large aperture having the double purpose of reducingweight and of permitting to the greatest pos- 4 sible extent the wearersleg to perspire and to come into contact the air.

In this way the artificial foot according to the invention can beconveniently fastened to the wearers leg and thigh, and the wearer canwalk normally on any type of ground whether the same is fiat orinclined, hard or soft.

If this artificial foot is to be fitted to a person with a considerableshortening of one leg, the form of the fixing frame or artificial legmust be modified, and suitably the construction of the hollow foot isalso slightly modified in order to adapt the same to the wearers foot,this modification is illustrated in Figures 8 to 10.

The framework for fixing the artificial foot to the wearers legcomprises a plate 45 which is adapted to the sole of the wearers footand which is articulated at 46 to the mechanism within the artificialfoot. The plate 45 is connected to the foot by means of a brace 42 andextends upwardly to form another brace 43 which is fixed to the wearersleg. In this case, the artificial foot comprises a hollow foot 41 whichis similar to the part 1 of the foot as shown in Figure 1 and whichcontains the mechanism which is substantially identical with themechanism as shown in Figures 3 to 7 and which operates in the same wayas the last-mentioned mechanism.

The mechanism of the foot as shown in Figures 8 to 10 comprises astamped sheet-metal framework 47 which is fixed to the sole of thehollow foot 41 and which has lateral lugs 48 by means of which theframework 47 is fixed to the lateral walls of the hollow foot 41. Theframework 47 has secured to itself the clamp 25 which is arranged to rubagainst the tubular piece 20. The latter is also surrounded by a clamp28 which in this case extends rcarwardly, forming the articulation point15 of the spring-loaded rod 10. The upper part 5 of the mechanism asillustrated in Figures 3 to 7 is substituted in Figures 8 to 10 by theplate 45 which is connected to the wearers foot and with which iscoupled the end of the spring-loaded rod 10. The articulation shaft 6 asshown in Figures 3 to 7 is substituted in this case by the articulationshaft 46 linking the plate 45 with the mechanism framework 4748.

The operation of this form of construction is exactly as hereinbeforedescribed with reference to Figures 3 to 7.

I claim:

1. An artificial leg comprising a hollow foot-shaped member having anupper and a lower part, an internal mechanism having an upper and lowerpart mounted within said foot-shaped member, said upper and lower partsof said internal mechanism being articulated to each other at the levelof a normal ankle joint, a spring loaded rod articulated on the upperpart of said internal mechanism, torsional spring means having one endconnected to said lower part of said internal mechanism, a tubularmember surrounding said torsional spring means to which the other end ofsaid torsional spring means is connected, a clamp on the lower part ofsaid internal mechanism in which said tubular member is rotatablyclamped, a second clamp rotatably clamped on said tubular member andhaving a pivot thereon to which the other end of said spring loaded rodis articulated, an upwardly directed extension on the upper part of saidfoot member, and means thereon for attachment to a wearers leg.

7 2. An artificial leg as claimed in claim 1 in which said second clamphas a plurality of lugs thereon and a shaft between said lugs formingthe pivot for the articulation of the end of said spring loaded rod, alateral extension on one of said lugs, and an arcuate portion on saidlower part of said internal mechanism against which said extension bearsfor limiting relative movement of said upper and lower parts of saidinternal mechanism.

3. An artificial leg as claimed in claim 1 in which said attachmentmeans comprise a cylindrical metal part on said extension fitting aroundthe part of a wearers leg below the knee, and a metal brace on saidextension for fitting around the thigh of a wearers leg, said extensionbeing articulated between said cylindrical metal part and said metalbrace at a point corresponding to a wearerfs knee.

4. An artificial leg as claimed in claim 3 in which said cylindricalmetal part is shaped in the form of a wearers leg from below the knee toabove the end of the leg, whereby the lower end of the leg isincompletely enclosed.

5. An artificial leg as claimed in claim 3 in which said metal brace hasa large aperture therein.

6. An artificial leg as claimed in claim 1 in which said means forattachment comprise a plate on said upper part of said internalmechanism for receiving the sole of the foot of a wearer, and means forattaching said plate to the foot, ankle and lower leg of a wearer, saidspring loaded rod being articulated to said upper part 0n the bottom ofsaid plate.

References Cited in the file of this patent UNITED STATES PATENTS 9,232Drake Aug. 31, 1852 2,542,436 Schultz Feb. 20, 1951 10 2,594,751Fahlstrom Apr. 29, 1952 FOREIGN PATENTS 628,958 Great Britain Sept. 8,1949

